Cognitive radio CSMA/CA protocol for femto-WLANs

To expand private femto-WLANs into public femto-WLANs, we present an integrated system of cognitive radio and femto-WLANs, cognitive femto-WLANs, which aims at meeting the requirements from the secondary users upon guaranteeing the requirements from the primary users. To reach this goal, we provide a cognitive radio CSMA/CA protocol, CR-CSMA/CA. Based on user differentiation, CR-CSMA/CA can provide a high priority for primary users, and a low priority for secondary users. Moreover, an analytical model is proposed to analyze the performance of CR-CSMA/CA under saturation cases. Extensive simulations are also carried out to evaluate the performance of CR-CSMA/CA.